package com.project.geonotes;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.UUID;

import android.content.Context;

public class Installation {
	private static String sID = null;
	private static final String INSTALLATION = "INSTALLATION";
	
	public synchronized static String id(Context context) {
        if (sID == null) {  
            File installation = new File(context.getFilesDir(), INSTALLATION);
            try {
                if (!installation.exists())
                    writeInstallationFile(installation);
                	sID = readInstallationFile(installation);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
        return sID;
    }
	 private static String readInstallationFile(File installation) throws IOException {
	        RandomAccessFile f = new RandomAccessFile(installation, "r");
	        byte[] bytes = new byte[(int) f.length()];
	        f.readFully(bytes);
	        f.close();
	        return new String(bytes);
	    }

	    private static void writeInstallationFile(File installation) throws IOException {
	        FileOutputStream out = new FileOutputStream(installation);
	        String id = UUID.randomUUID().toString();
	        out.write(id.getBytes());
	        out.close();
	    }
}
